Storage and transmission of data signals



Oct. 19, 1965 G. DIRKS 3,213,437

STORAGE AND TRANSMISSION OF DATA SIGNALS Original Filed Nov. 28, 1958AMP 33 I? 15 AMP AMP INVENTOR Qmmmv pm BYW W ATTOZNEY United StatesPatent 3,213,437 STORAGE AND TRANSMISSION OF DATA SIGNALS Gerhard Dirks,44 Moerfelder Landstrasse, Frankfurt am Main, Germany Continuation ofapplication Ser. No. 777,119, Nov. 28, 1958. This appiication July 10,1961, Scr. No. 126,771 Claims priority, application Great Britain, Dec.9, 1957, 38,416/57 24 Claims. (Cl. 340174.1)

This application is a continuation-application of pending patentapplication Serial No. 777,119, filed November 28, 1958, and entitledStorage and Transmission of Data Signals, now abandoned.

This invention relates to cyclically operable magnetic data storageapparatus.

Magnetic drums and discs are well known for use as data storage devices.They are usually provided with one or more timing signal tracks whichare used to control address counters. These counters control thesclection of data items from the data tracks on the drum. The address ofeach data item is thus specified by the position of the area in which itis recorded relative to the fixed timing signals. Normally a singlepulse is recorded in one timing track to act as an end of revolutionmarker pulse, which provides the reference by which the data storagepositions may be identified.

It has been the practice to provide a buffer store, such as a shiftingregister, to allow data items arriving at random times to be recorded inthe required position on the drum or disc. The data is held in thebuffer store until the required area is available to the recording head.

It is an object of the invention to simplify the recording of data on acyclic magnetic store in a fixed position relative to a reference pointof the store.

It is another object of the invention to control the rotation of acyclic magnetic storage device to allow recording of a data item tostart at a predetermined point in a recording track.

In accordance with one embodiment of the invention, the cyclicallyoperable data storage apparatus includes a rotatable storage memberbearing a magnetic signal recording track, a recording head cooperatingwith the track, a source of signal trains to be recorded, means to applya signal train to the recording head, latching means settable to anetfective position in which the storage member is held in apredetermined position and to an ineffective position in which thestorage member is allowed to rotate and means responsive to said signalsfrom the signal source to set the latching means to the ineffectiveposition to cause recording of the signal train to start at apredetermined point in the recording track.

The invention may also be embodied in a cyclically operable data storageapparatus which includes a rotatable storage member With a magneticsignal recording track thereon, a recording head cooperating with therecording track, a record member bearing a group of data representingsignals, signal sensing means past which the record member is moved,means for applying signals from the sensing means to the recording head,latching means settable to an effective position in which the storagemember is held in a predetermined position and to an ineffectiveposition in which the storage member is allowed to rotate, and meansresponsive to signals from the sensing means to set the latching meansto the ineffective position to cause recording of the sensed signals tostart at a predetermined point in the recording track.

The invention will now be described, by way of example, with referenceto the accompanying drawing, in which:

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FIG. 1 is a schematic diagram of an arrangement for recording signals ona magnetic drum under control of signals sensed from another magneticdrum; and

FIG. 2 is a schematic diagram of a modified arrangement in which thesignals to be recorded are sensed from a magnetic tape.

Referring now to FIG. 1, magnetic storage drum 1 is shown mounted on ashaft 2, which is rotated continuously in the direction of arrow 3 by amotor 4. A second magnetic storage drum 5 is mounted on a shaft 6, whichis coupled to the shaft 2 through a friction clutch 7. The clutch may beof any conventional type which will drive the shaft 6 under lightloading conditions and which will slip when the shaft 6 is restrained.For example it may consist of a disc secured to the shaft 2 and asimilar disc splined on the shaft 6 and lightly sprung towards the firstdisc, the opposing faces of the two discs being covered with a suitablefrictional material.

The shaft 6 carries a projection 8 which is normally engaged by one armof an L-shaped latch 9. The latch is pivotally attached at 10 to asupport 11. A spring 12 acts on the other arm of the latch 9 to hold itin engagement with the projection 8. The movement of the latch islimited by a stop 13. An electromagnet 14 is mounted on the support 11adjacent to an arm of the latch. On energization, the electromagnetattracts the latch arm, which rotates in a counter-clockwise directionand is thereby disengaged from the projection 8.

Normally the electromagnet 14 is not energized and the latch 9 engagesthe projection 8. The clutch 7 slips and holds the projection againstthe latch, so that the drum 5 is held stationary in a known position.When the electromagnet is energized the latch is shifted out ofengagement and the drum is released for rotation.

The drum 1 has a data signal recording track 15. Signals from a datainput source 16 may be recorded in the track 15 by shifting a switch 18.This allows signals to be fed from the input 16 through amplifier 17 andswitch 18, to a recording head 19 which is associated with the track 15.

The signals from the input 16 preferably occur in groups, each groupforming a data word. The length of the track 15 is sufiicient to storemore than one word, preferably, at least two words. The data input isnot synchronized with the drum 1 and the data signals are recorded asthey occur. Hence, a word may be recorded at any position in the track15. A word randomly recorded in the track 15 in this manner is to berecorded in a track 20 on the drum 5, with the recording starting in apredetermined position in the track which is indicated by a chaindottedline 21.

In order to record a word in the track 20, the switch 18 is set to theposition shown in FIG. 1 and switch 22 is closed. A magnetic head 23senses any signals recorded in the track 15 of the drum 1. The head 23drives a reading amplifier 24, the output of which is fed through thethen closed switch 22 to the input of a conventional two tubemono-stable flipfiop 25. The first signal fed to the flipfiop by theamplifier 24 switches the flip-flop on. The time constant of theflipfiop is such that it switches off after a time slightly greater thanthat required to sense a word from the track 15. One anode of theflip-flop 25 is capacitatively coupled to the input of a conventionaltwo tube bi-stable fiip-fiop 26, so that the flip-flop 25 in switchingoff applies a pulse which switches on the flip-flop 26.

The output of the amplifier 24 is also fed to one grid of a conventionalpentode gate 27. The potential of the other grid of the gate iscontrolled by the flip-flop 26. The gate is closed or open in accordancewith whether the flip-flop 26 is oil or on. Thus the gate 27 does notpass the signals from the amplifier 24 which cause switching of theflip-flop 2. However, the word recorded in the track will be sensedagain during the next revolution of the drum 1. The flip-flop 26 is thenon and the signals are passed by the gate 27 to the input of a secondmono-stable flip-flop 28 and to the control grid of a gas-filled tube29. The first signal passed by the gate 27 switches on the flipflop 28and fires the tube 29. The anode of the tube 29 is connected through aparallel capacitor and resistor combination 30, 31 and the winding ofthe electromagnet 14 to a positive supply terminal 32. The anode of thetube v 29 is normally at the positive supply voltage. When the tube isfired the anode current consists of the charging current of the caacitor30, together with the current flowing through the resistor 31. Thisresistor cannot pass sulficicnt current to maintain the tube conducting.Hence, as the charging current falls a point is reached at which thetube extinguishes. The capacitor then discharges through the resistor31.

The pulse of anode current passed by the tube 29 energizes theelectromagnet 14 to withdraw the latch 9 from engagement with theprojection 8. This releases the shaft 6, carrying the drum 5, and allowsit to be driven through the clutch 7. The latch is returned by thespring 12 when the electromagnet is tie-energized and rcengages theprojection 8 after one revolution of the shaft 6.

The flip-flop 28 controls a gate 3, the gate being open when theflip-flop is on. In this condition the signals from the head 19 are fedthrough the switch 18, an amplifier 34, and the gate 3 to a recordinghead 35 which records in the track 20. The head 23 is positioned inadvance of 3 the head 19, so that the drum is released for rotationunder control of the signals sensed by the head 23 and has time toaccelerate to approximately the speed of the drum 1 before the samesignals are sensed by the head 19. The

spacing between the heads 19 and 23 is such that the part 5 of the track20 indicated by the line 21 is passing the head 35 at the time when thefirst signal in the track 15 is sensed by the head 19. Since therotation of the drum 5 is initiated by pre-sensing of the start of aword in the track 15, recording of the word in the track 20 will alwayscommence at the part of the track indicated by 21.

The time constant of the mono-stable flip-flop 28 is such that itswitches off just after the word in track 15 has been completely sensedby the head 19. The fiipfiop 28 is capacitatively coupled to an input ofthe flip-flop 26. The i switching ofi' of the flip-flop 28 applies apulse to the fliptlop 26 to switch it otf, thus returning the circuit tothe initial condition.

It will be appreciated that the latch and clutch may take differentforms, provided that the shaft 6 is held in a predetermined position andthat the shaft may be released in response to an electrical signal. Forexample, the separate clutch and latch may be replaced by anelectromagnetically controlled one revolution clutch. Such clutches arewell known in relation to record card controlled machines, forcontrolling the feeding of cards from a stack, for example.

The drum may normally be freely driven through the clutch 7 and bearrested only just before a recording is to be made. This modificationis shown in FIG. 2 in an arrangement for recording data derived from amagnetic tape 36, instead of from the drum 1. The magnetic tape 36 isfed in the direction of arrow 37 by the usual feeding mechanismrepresented schematically by a roller 38 and a motor 39. It isconvenient in this case to use a separate motor 40 for driving the drum5 through the clutch 7.

The latch 9 is normally held against a stop 41 by a spring 42, so thatthe latch is clear of the projection 8. Thus the drum is normallyrotated by the motor 40. The electromagnet 14 is positioned so that itbrings the latch into the path of the projection 8, when theelectromagnet is energized. The electromagnet is energized by a poweramplifier 43 which is D.C. coupled to a bistable fiipfiop 44. Theamplifier is non-conducting when the flip-flop 44 Ill is off andconducts heavily to energize the elcctromagnct 14 as long as theflip-flop is on.

The state of the flip-flop 44 is controlled by signals from magneticheads 45 and 46, which sense a track 47 on the tape 36. The heads 45 and46 are spaced apart by a distance such that rather more than onerevolution of the drum occurs between the sensing of a signal by thehead 45 and the sensing of the same signal by the head 46.

Signals sensed by the head 45 are fed through an amplifier 48 to oneinput of the flip-flop 44. The flip-flop 44 is normally off and isswitched on by the first signal of a Word sensed by the head 45. Thismakes the amplifier 43 conduct and energizes the electromagnet 14, whichmoves the latch 9 into the path of the projection 8. At some time duringthe next revolution of the drum 5, the projection will engage the latchand the drum will be brought to rest and held until the flip-flop 44 isswitched off.

After rather more than the time for one drum revolution, the signalwhich was sensed by the head 45 to switch on the flip-flop 44 will besensed by the head 46 This head is connected to the input of anamplifier 49, the output of which is connected to the input of aconventional lumped constant delay line circuit 50 and to the otherinput of the flip-flop 44. This first signal of the word switches offthe flip-flop 44, thus de-energizing the electromagnet 14 and allowingthe spring 42 to pull the latch 9 clear of the projection 8. The drum 5is now free to rotate. The delay imposed by the delay circuit 50 on thesignals from the amplifier 49 is such that the first signal of the wordis fed through an amplifier 51 to the head 35 at the time when the partof the track indicated by 21 is passing the head. Thus recording of theword will start at the required predetermined point in the track 20.

It has been explained that it is necessary to have a delay between thesensing of the signals for controlling the release of the drum 5 and therecording of the same signals on the drum 5. In the arrangement of FIG.I this is provided by the spacing apart of the heads 23 and 19, and inFIG. 2 by the delay circuit 59.

The recording always starts at the pre-determined point of the track 20.Consequently, a second word or block of data will be recorded overpreviously recorded data. In order to preserve the data, the drum mayhave a number of tracks similar to the track 20, each track having anassociated recording head, these heads being connected in turn to thegate 33 (FIG. 1) or the amplifier 51 (FIG. 2) by a conventional headswitching arrangement. Alternatively, a reading head (not shown) may beprovided for the track 20 so that the data may be read out before it iserased by overwriting of further data.

A limited amount of data is recorded in the track 20 during any onerecording operation, so that a short length of track sutfices.Therefore, the drum 5 may be of relatively small diameter with arelatively low inertia.

It will be appreciated that the track 20 may equally well be on a discas on a drum. The signals to be recorded in the track 20 may be derivedfrom the sensing of record cards or paper tape, instead of from a drumor magnetic tape as described above.

What I claim is:

1. In a data storage arrangement, in combination, a first continuouslymoving recording medium having data signals recorded thereon; a secondrecording medium adapted to be rotated; rotating means for rotating saidsecond recording medium; circuit means interconnecting said first andsecond recording medium; a prcsensing head in operative proximity withsaid first rccording medium for energizing through said circuit meanssaid rotating means to rotate said second recording medium under thecontrol of a presensed one of said data signals; and a sensing headspaced behind said presensing head in operative proximity with saidfirst recording medium for supplying said data signals from said firstrecording medium to said second recording medium through said circuitmeans a predetermined period of time after said rotating means isenergized.

2. In a data storage arrangement, in combination, a first continuouslymoving recording medium having data sig nals recorded thereon; a secondrecording medium adapted to be rotated; rotating means for rotating saidsecond recording medium, said rotating means including electromagneticmeans for controlling the rotating of said second recording medium, saidelectromagnetic means being adapted to be controlled by a data signal;circuit means interconnecting said first and second recording mediums; apresensing head in operative proximity with said first recording mediumfor energizing through said circuit means the electromagnetic means ofsaid rotating means to rotate said second recording medium under thecontrol of a presenscd one of said data signals, said presensing headbeing connected to said circuit means; and a sensing head spaced behindsaid presensing head in operative proximity with said first recordingmedium for supplying said data signals from said first recording mediumto said second recording medium through said circuit means apredetermined period of time after the electromagnetic means of saidrotating means is energized.

3. In a data storage arrangement, in combination, a first continuouslymoving recording medium having data signals recorded thereon; a secondrecording medium; circuit means interconnecting said first and secondrecording mediums; presensing means in operative proximity with saidfirst recording medium for providing a signal path through said circuitmeans between said first and second recording mediums under the controlof a presensed one of said data signals; and sensing means spaced behindsaid presensing means in operative proximity with said first recordingmedium for supplying said data signal from said first recording mediumto said second recording medium through said signal path a predeterminedperiod of time after said signal path is provided by said presensed datasignal.

4. In a data storage arrangement, in combination, a first continuouslymoving recording medium having data signals recorded thereon; a secondrecording medium adapted to be rotated; rotating means for rotating saidsecond recording medium; circuit means interconnecting said first andsecond recording mediums; a presensing head in operative proximity withsaid first recording medium for providing a signal path through saidcircuit means between said first and second recording mediums and forenergizing said rotating means to rotate said second recording mediumunder the control of a presenscd one of said data signals; and a sensinghead spaced behind said presensing head in operative proximity with saidfirst recording medium for supplying said data signals from said firstrecording medium to said second recording medium through said signalpath a predetermined period of time after said signal path is providedby said presenscd data signal.

5. In a data storage arrangement, in combination, a first continuouslymoving recording medium having data signals recorded thereon; a secondrecording medium adapted to be rotated; rotating means for rotating saidsecond recording medium, said rotating means including electromagneticmeans for controlling the rotating of said second recording medium, saidelectromagnetic means being adapted to be controlled by a data signal;circuit means interconnecting said first and second recording mediums; apresensing head in operative proximity with said first recording mediumfor providing a signal path through said circuit means between saidfirst and second recording mediums and for energizing theelectromagnetic means of said rotating means to rotate said secondrecording medium under the control of a presenscd one of said datasignals, said presensing head being connected to said cir cuit means andto said electromagnetic means; and a sensing head spaced behind saidpresensing head in operative proximity with said first recording mediumfor supplying said data signals from said first recording medium to saidsecond recording medium through said signal path a predetermined periodof time after said signal path is provided by said presenscd data signaland after the electromagnetic means of said rotating means is energized.

6. A data storage arrangement comprising, in combination, firstcontinuously moving storage means having data signals recorded thereon,said data signals forming a data unit commencing with a first datasignal and ending with a last data signal; second storage means comprising a rotatable recording medium; rotating means for rotating saidrotatable recording medium; transfer means connected between said firstand second storage means for transferring said data signals from saidfirst storage means to said second storage means; transfer control meansconnected to said transfer means; presensing means in operativeproximity with said first storage means for sensing said data signals,for energizing said transfer control means with said first data signalto open said transfer means to permit the transfer of data signalstherethrough, and for energizing said rotating means to initiaterotation of said rotatable recording medium; and sensing means spacedbehind said presensing means in operative proximity with said firststorage means for sensing said data signals a predetermined period oftime after said data signals are sensed by said presensing means and forsupplying said data signals from said first storage means to said secondstorage means through said transfer means.

7. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording medium having data signals recorded thereon, said data signalsforming data unit commencing with a first data signal and ending with alast data signal; second storage means comprising a rotatable recordingmedium; rotating means for rotating said rotatable recording medium;transfer means connected between said first and second storage means fortransferring said data signals from said first storage means to saidsecond storage means; transfer control means connected to said transfermeans; presensing means in operative proximity with said first storagemeans for sensing said data signals for energizing said transfer controlmeans with said first data signal to open said transfer means to permitthe transfer of data signals therethrough, and for energizing saidrotating means to initiate rotation of said rotatable recording medium;and sensing means spaced behind said presensing means in operativeproximity with said first storage means for sensing said data signals apredetermined period of time after said data signals are sensed by saidpresensing means and for supplying said data signals from said firststorage means to said second storage means through said transfer means,said predetermined period of time being of a duration sutlicient toenable the speed of rotation of said second storage means to reach thespeed of rotation of said first storage means.

8. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording meduim, said rotatingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing With a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; rotating meansfor rotating said rotatable recording medium; transfer means connectedbetween said first and second storage means for transferring said datasignals from said first storage means to said second storage means;transfer control means connected to said transfer means; presensingmeans in operative proximity with said first storage means for sensingsaid data signals, for energizing said transfer control means with saidfirst data signal to open said transfer means to permit the transfer ofdata signals therethrough, and for energizing said rotating means toinitiate rotation of said rotatable recording medium; and sensing meansspaced behind said presensing means in operative proximity with saidfirst storage means for sensing said data signals a predetermined periodof time after said data signals are sensed by said presensing means andfor supplying said data signals from said first storage means to saidsecond storage means through said transfer means, said predeterminedperiod of time being of a duration selected so that said first datasignal transferred through said transfer means reaches said rotatablerecording medium at the fixed starting place thereon.

9. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously ro tating recording medium, saidrotating recording medium having data signals recorded thereon, saiddata signals forming a data unit commencing with a first data signal andending with a last data signal; second storage means comprising arotatable recording medium having a fixed starting place thereon;rotating means for rotating said rotatable recording medium; transfermeans connected be tween said first and second storage means fortransferring said data signals from said first storage means to saidsecond storage means; transfer control means connected to said transfermeans; presensing means in operative proximity with said first storagemeans for sensing said data signals, for energizing said transfercontrol means with said first data signal to open said transfer means topermit the transfer of data signals therethrough, and for energizingsaid rotating means to initiate rotation of said rotatable recordingmedium; and sensing means spaced behind said presensing means inoperative proximity with said first storage means for sensing said datasignals a predetermined period of time after said data signals aresensed by said presensing means and for supplying said data signals fromsaid first storage means to said second storage means through saidtransfer means, said predetermined period of time being of a durationselected so that said first data signal transferred through saidtransfer means reaches said rotatable recording medium at the fixedstarting place thereon and sufiicient to enable the speed of rotation ofsaid second storage means to reach the speed of rotation of said firststorage means.

10. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; rotating meansfor rotating said rotatable recording medium; transfer means connectedbetween said first and second storage means for transferring said datasignals from said rotating recording medium to said rotatable recordingmedium; transfer control means connected to said transfer means; apresensing head positioned in operative proximity with said rotatingrecording medium for sensing said data signals, for energizing saidtransfer control means to permit the transfer of data signalstherethrough, and for energizing said rotating means to initiaterotation of said rotatable recording medium, said presensing head beingcoupled to said transfer control means and to said rotating means; asensing head spaced behind said presensing head in operative proximitywith said rotating recording medium for sensing said data signals apredetermined period of time after said data signals are sensed by saidpresensing head and for supplying said data signals from said rotatingrecord ing medium to said rotatable recording medium through saidtransfer means, said sensing head being coupled to said transfer means;and a recording head positioned in operative proximity with saidrotatable recording medium, said recording head being coupled to saidtransfer means.

11. A data storage arrangement comprising, in combination, a firststorage means comprising a continuously rotating recording medium, saidrotating recording medium having data signals recorded thereon, saiddata signals forming a data unit commencing with a first data signal andending with a last data signal; a presensing head positioned inoperative proximity with said rotating recording medium for sensing saiddata signals; a sensing head spaced between said prescnsing headpositioned in operative proximity with said rotating recording mediumfor sensing said data signals a predetermined period of time after saiddata signals are sensed by said presensing head; second storage meanscomprising a rotatable recording medium having a fixed starting placethereon; a recording head positioned in operative proximity with saidrotatable recording medium; rotating means for rotating said rotatablerecording medium; transfer means connected between said sensing head andsaid recording head for transferring said data signals fom said rotatingrecording medium to said rotatable recording medium; transfer controlmeans connected between said presensing head and said transfer means forcontrolling the transfer of data signals through said transfer means;and coupling means coupling said presensing head to said rotating meansso that said presensing head controls the operation of said rotatingmeans to initiate rotation of. said rotatable recording medium.

12. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; a presensing head positioned in operative proximitywith said rotating recording medium for sensing said data signals; asensing head spaced behind said presensing head positioned in operativeproximity with said rotating recording medium for sensing said datasignals a predetermined period of time after said data signals aresensed by said presensing head; second storage means comprising arotatable recording medium having a fixed starting place thereon; arecording head positioned in operative proximity with said rotatablerecording medium; rotating means for rotating said rotatable recordingmedium; transfer means connected between said sensing head and saidrecording head for transferring said data signals from said rotatingrecording medium to said rotatable recording medium, said transfer meanscomprising an electronic device having an input connected to saidsensing head, an output connected to said recording head and conductioncontrol means; transfer control means connected between said presensinghead and said transfer means for controlling the transfer of datasignals through said transfer means, said transfer control meanscomprising electronic circuit means having an input connected to saidpresensing head and an output connected to the conduction control meansof said electronic device; and coupling means coupling said presensinghead to said rotating means so that said presensing head controls theoperation of said rotating means to initiate rotation of said rotatablerecording medium.

13. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording me dium having data signals recorded thereon, said datasignals forming a data unit commencing with a first data signal andending with a last data signal; a presensing head positioned inoperative proximity with said rotating recording medium for sensing saiddata signals; a sensing head spaced behind said presensing headpositioned in operative proximity with said rotating recording mediumfor sensing said data signals a predetermined period of time after saiddata signals are sensed by said presensing head; second storage meanscomprising a rotatable recording medium having a fixed starting placethereon; a recording head positioned in operative proximity with saidrotatable recording medium; rotating means for rotating said rotatablerecording medium; transfer means connected between said sensing head andsaid recording head for transferring said data signals from saidrotating recording medium to said rotatable recording medium, saidtransfer means comprising an electronic gate having an input connectedto said sensing head, an output connected to said recording head andconduction control means, said gate being adapted to maintain under thecontrol of its conduction control means one of an open condition inwhich a substantially low impedance sufficient to conduct said datasignals is presented between the input of said gate and the outputthereof and a closed condition in which a substantially high impedancesufiicient to block said data signals is presented between the input ofsaid gate and the output thereof; transfer control means connectedbetween said presensing head and said transfer means for controlling thetransfer of data signals through said transfer means, said transfercontrol means comprising electronic circuit means having an inputconnected to said presensing head and an output connected to theconduction control means of said electronic device; and coupling meanscoupling said presensing head to said rotating means so that saidpresensing head controls the operation of said rotating means toinitiate rotation of said rotatable recording medium.

14. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; a presensing head positioned in operative proximitywith said rotating recording medium for sensing said data signals; asensing head spaced between said presensing head positioned in operativeproximity with said rotating recording medium for sensing said datasignals a predetermined period of time after said data signals aresensed by said presensing head; second storage means comprising arotatable recording medium having a fixed starting place thereon; a recording head positioned in operative proximity with said rotatablerecording medium; rotating means for rotating said rotatable recordingmedium; transfer means connected between said sensing head and saidrecording head for transferring said data signals from said rotatingrecording medium to said rotatable recording medium, said transfer meanscomprising an electronic gate having an input connected to said sensinghead, an output con nected to said recording head and conduction controlmeans, said gate being adapted to maintain under the control of itsconduction control means one of an open condition in which asubstantially low impedance sulficient to conduct said data signals ispresented between the input of said gate and the output thereof and aclosed condition in which a substantially high impedance sufficient toblock said data signals is presented between the input of said gate andthe output thereof; transfer control means connected between saidpresensing head and said transfer means for controlling the transfer ofdata signals through said transfer means, said transfer control meanscomprising multivibrator circuit means and gate means connected incircuit between said presensing head and the conduction control means ofsaid electronic gate; and coupling means coupling said presensing headto said rotating means so that said presensing head controls theoperation of said rotating means to initiate rotation of said rotatablerecording medium, said coupling means including the gate means of saidcircuit and a coupling connection between said gate means and saidrotating means, said predetermined period of time being of a durationselected so that said first data signal transferred through saidtransfer means reaches said rotatable recording medium at the fixedstarting place thereon and sulficient to enable the speed of rotation ofsaid second storage means to reach the speed of rotation of said firststorage means.

15. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously rotating recording medium, said rotatingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; a presensing head positioned in operative proximitywith said rotating recording medium for sensing said data signals; asensing head spaced behind said presensing head positioned in operativeproximity with said rotating recording medium for sensing said datasignals a predetermined period of time after said data signals aresensed by said presensing head; second storage means comprising arotatable recording medium having a fixed starting place thereon; arecording head positioned in operative proximity with said rotatablerecording medium; rotating means for rotating said rotatable recordingmedium; coupling means coupling said presensing head to said rotatingmeans so that said presensing head controls the operation of saidrotating means to initiate rotation of said rotatable recording medium;transfer means connected between said sensing head and said recordinghead for transferring said data signals from said rotating recordingmedium to said rotatable recording medium, said transfer meanscomprising a first gate having an input connected to said sensing head,an output connected to said recording head and conduction control means,said first gate being adapted to maintain under the control of itsconduction control means one of an open condition in which it conductssaid data signals between its input and output and a closed condition inwhich it blocks said data signals; and transfer control means connectedbetween said presensing head and the conduction control means of. saidfirst gate for controlling the transfer of data signals through saidtransfer means, said transfer control means comprising a firstmonostable multivibrator having a first output connected to theconduction control means of said first gate, a second output and aninput, a second gate having an input connected to said presensing head,an output connected to the input of said first monostable multivibratorand conduction control means, said second gate being adapted to maintainunder the control of its conduction control means one of an opencondition in which it conducts said data signals between its input andoutput and a closed condition in which it blocks said data signals, andmultivibrator circuit means connected between said presensing head andthe conduction control means of said second gate for controlling inaccordance with a predetermined time sequence the condition of saidsecond gate and thereby controlling the condition of said first gatethrough said monostable multivibrator, and said coupling means includingsaid second gate and a coupling connection between the output of saidsecond gate and said rotating means so that said multivibrator circuitmeans also controls the operation of said rotating means through saidsecond gate.

16. A data storage arrangement, comprising, in combination, firststorage means comprising a continuously rotating recording medium, saidrotating recording medium having data signals recorded thereon, saiddata signals forming a data unit commencing with a first data signal andending with a last data signal; a presensing head positioned inoperative proximity with said rotating recording medium for sensing saiddata signals; a sensing head spaced behind said presensing headpositioned in operative proximity with said rotating recording mediumfor sensing said data signals a predetermined period of time after saiddata signals are sensed by said presensing head; second storage meanscomprising a rotatable recording medium having a fixed starting placethereon; :1 recording head positioned in operative proximity with saidrotatable recording medium; rotating means for rotating said rotatablerecording medium; coupling means coupling said presensing head to saidrotating means so that said presensing head controls the operation ofsaid rotating means to initiate rotation of said rotatable recordingmedium; transfer means connected between said sensing head and saidrecording head for transferring said data signals from said rotatingrecording medium to said rotatable recording medium, said transfer meanscomprising a first gate having an input connected to said sensing head,an output connected to said recording head and conduction control means,said first gate being adapted to maintain under the control of itsconduction control means one of an open condition in which it conductssaid data signals between its input and output and a closed condition inwhich it blocks said data signals; and transfer control means connectedbetween said presensing head and the conduction control means of saidfirst gate for controlling the transfer of data signals through saidtransfer means, said transfer control means comprising a firstmonostable multivibrator having a first output connected to theconduction control means of said first gate, a second output and aninput, a second gate having an input connected to said presensing head,an output connected to the input of said first monostable multivibratorand conduction control means, said second gate being adapted to maintainunder the control of its conduction control means one of an opencondition in which it conducts said data signals between its input andoutput and a closed condition in which it blocks said data signals, andmultivibrator circuit means connected between said presensing head andthe conduction control means of said second gate for controlling inaccordance with a predetermined time sequence the condition of said sec-0nd gate and thereby controlling the condition of said first gatethrough said monostable multivibrator, and said coupling means includingsaid second gate and a coupling connection between the output of saidsecond gate and said rotating means so that said multivibrator circuitmeans also controls the operation of said rotating means through saidsecond gate, said multivibrator circuit comprising a bistablemultivibrator having a first input connected to the second output ofsaid first monostable multivibrator, a second input and an outputconnected to the conduction control means of said second gate, and asecond monostable multivibrator having an input connected to saidpresensing head and an output connected to the second input of saidbistable rnultivibrator.

17. Apparatus for magnetically recording signals in predeterminedlocations comprising a continuously rotatable storage member having amagnetizable track; a recording head positioned to write on said track;a motor coupled by a clutch to said storage member; a locking mechanismfor preventing rotation of said storage member; a first source ofelectrical signals; a second source providing said electrical signalsafter a predetermined interval of time; a first gate having its outputcoupled to said recording head and its input connected to said secondsource; a second gate having its input excited by signals from saidfirst source; a trigger generator responsive to a signal from said firstsource for providing a delayed trigger; a bistable device holding saidsecond gate closed when said device is in a first stable state, saidbistable device being set into its second stable state by said delayedtrigger; means responsive to a signal transmitted through said secondgate for releasing said locking mechanism to permit said storage memberto rotate; and a monostable device holding said first gate closed whensaid device is in its stable condition, said monostable device beingtriggered to its unstable condition by the output of said second gatewhereby said first gate is opened, and said monostable device uponreturning to its initial condition causing said bistable device to bereset.

13. A data storage arrangement comprising, in combination, firstcontinuously moving storage means having data signals recorded thereon,said data signals forming lll a data unit commencing with a first datasignal and ending with a last data signal; second storage meanscomprising a rotatable recording medium; rotating means for rotatingsaid rotatable recording medium; transfer means connected between saidfirst and second storage means for transferring said data signals fromsaid first storage means to said second storage means; presensing meansin operative proximity with said first storage means for sensing saiddata signals and for conditioning said rotating means for initiatingrotation of said rotatable recording edium; and sensing means spacedbehind said presensing means in operative proximity with said firststorage means for sensing said data signals for energizing said rotatingmeans to initiate rotation of said rotatable recording medium and forsupplying said data signals from said first storage means to said secondstorage means through said transfer means a predetermined period of timeafter said rotating means is energized.

19. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium; rotating means for rotating said rotatable recordingmedium; transfer means connected between said first and second storagemeans for transferring said data signals from said first storage meansto said second storage means; presenting means in operative proximitywith said first storage means for sensing said data signals and forconditioning said rotating means for initiating rotation of saidrotatable recording medium; and sensing means spaced behind saidpresensing means in operative proximity with said first storage meansfor sensing said data signals for energizing said rotating means toinitiate rotation of said rotatable recording medium and for supplyingsaid data signals from said first storage means to said second storagemeans through said transfer means a predetermined period of time aftersaid rotating means is energized, said predetermined period of timebeing of a duration sufficient to enable the speed of rotation of saidsecond storage means to reach the speed of rotation of said firststorage means.

20. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; rotating meansfor rotating said rotatable recording medium; transfer means connectedbetween said first and second storage means for transferring said datasignals from said first storage means to said second storage means;presensing means in operative proximity with said first storage meansfor sensing said data signals and for conditioning said rotating meansfor initiating rotation of said rotatable recording medium; and sensingmeans spaced between said presensing means in operative proximity withsaid first storage means for sensing said data signals for energizingsaid rotating means to initiate rotation of said rotatable recordingmedium and for supplying said data signals from said first storage meansto said second storage means through said transfer means a predeterminedperiod of time after said rotating means is energized, saidpredetermined period of time being of a duration selected so that saidfirst data signal transferred through said transfer means reaches saidrotatable recording medium at the fixed starting place thereon.

21. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; rotating meansfor rotating said rotatable recording medium; transfer means connectedbetween said first and second storage means for transferring said datasignals from said first storage means to said second storage means;presensing means in operative proximity with said first storage meansfor sensing said data signals and for conditioning said rotating meansfor initiating rotation of said rotatable recording medium; and sensingmeans spaced behind said presensing means in operative proximity withsaid first storage means for sensing said data signals for energizingsaid rotating means to initiate rotation of said rotatable recordingmedium and for supplying said data signals from said first storage meansto said second storage means through said transfer means a predeterminedperiod of time after aid rotating means is energized, said predeterminedperiod of time being of a duration selected so that said first datasignal transferred through said transfer means reaches said rotatablerecording medium at the fixed starting place thereon and sufficicnt toenable the speed of rotation of said second storage means to reach thespeed of movement of said first storage means.

22. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium having data signals recorded thereon, said data signalsforming a data unit commencing with a first data signal and ending witha last data signal; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; rotating meansfor rotating said rotatable recording medium; transfer means connectedbetween said first and second storage means for transferring said datasignals from said moving recording medium to said rotatable recordingmedium; a presensing head positioned in operative proximity with saidmoving recording medium for sensing said data signals and forconditioning said rotating means for initiating rotation of saidrotatable recording medium, said presensing head being coupled to saidrotating means; a sensing head spaced behind said presensing headpositioned in operative proximity with said moving recording medium forsensing said data signals for energizing said rotating means to initiaterotation of said rotatable recording medium and for supplying said datasignals from said first storage means to said second storage meansthrough said transfer means a predetermined period of time after saidrotating means is energized, said sensing head being coupled to saidtransfer meansand to said rotating means; and a recording headpositioned in operative proximity with said rotatable recording medium,said recording head being coupled to said transfer means.

23. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium having data signals recorded thereon, said data signalslit forming a data unit commencing with a first data signal and endingwith a last data signal; a presensing head positioned in operativeproximity with said moving recording medium for sensing said datasignals; a sensing head spaced behind said presensing head positioned inoperative proximity With said moving recording medium for sensing saiddata signals; second storage means comprising a rotatable recordingmedium having a fixed starting place thereon; a recording headpositioned in operative proximity with said rotatable recording medium;rotating means for rotating said rotatable recording medium; firstcoupling means coupling said presensing head to said rotating means sothat said presensing head conditions said rotating means for operationalcontrol thereof; second coupling means coupling said sensing head tosaid rotating means so that said sensing head controls the operation ofsaid rotating means to initiate rotation of said rotatable recordingmedium; and transfer means connected between said sensing head and saidrecording head for transferring said data signals from said movingrecording medium to said rotatable recording medium a predeterminedperiod of time after rotation of said rotatable recording medium isinitiated.

24. A data storage arrangement comprising, in combination, first storagemeans comprising a continuously moving recording medium, said movingrecording medium forming a data unit commencing with a first data signaland ending with a last data signal; a presensing head positioned inoperative proximity with said moving recording medium for sensing saiddata signals; a sensing head spaced behind said presensing headpositioned in operative proximity with said moving recording medium forsensing said data signals; second storage means comprising a rotatablerecording medium having a fixed starting place thereon; a recording headpositioned in operative proximity with said rotatable recording medium;rotating means for rotating said rotatable recording medium; a bistablemultivibrator having a first input coupled to said presensing head, asecond input coupled to said sensing head and an output coupled to saidrotating means; and transfer means connected between said sensing headand said recording head for transferring said data signals from saidmoving recording medium to said rotatable recording medium apredetermined period of time after rotation of said rotatable recordingmedium is initiated, said transfer means comprising time delay meansconnected between said sensing head and said recording head.

References Cited by the Examiner UNITED STATES PATENTS 2,561,869 7/51Kent 346-44 X 2,700,067 1/55 Lockemann et a1. 340-l74.1 X 3,013,25412/61 Walker 34674 X IRVING L. SRAGOW, Primary Examiner.

BERNARD KONICK, Examiner.

16. A DATA STORAGE ARRANGEMENT, COMPRISING, IN COMBINATION, FIRSTSTORAGE MEANS COMPRISING A CONTINUOUSLY ROTATING RECORDING MEDIUM, SAIDROTATING RECORDING MEDIUM HAVING DATA SIGNALS RECORDED THEREON, SAIDDATA SIGNALS FORMING A DATA UNIT COMMENCING WITH A FIRST DATA SIGNAL ANDENDING WITH A LAST DATA SIGNAL; A PRESENSING HEAD POSITIONED INOPERATIVE PROXIMITY WITH SAID ROTATING RECORDING MEDIUM FOR SENSING SAIDDATA SIGNALS; A SENSING HEAD SPACED BEHIND SAID PRESENSING HEADPOSITIONED IN OPERATIVE PROXIMITY WITH SAID ROTATING RECORDING MEDIUMFOR SENSING SAID DATA SIGNALS A PREDETERMINED PERIOD OF TIME AFTER SAIDDATA SIGNALS A PREDETERMINED PERIOD OF HEAD; SECOND STORAGE MEANSCOMPRISING A ROTATABLE RECORDING MEDIUM HAVING A FIXED STARTING PLACETHEREON; A RECORDING HEAD POSITIONED IN OPERATIVE PROXIMITY WITH SAIDROTATABLE RECORDING MEDIUM; ROTATING MEANS FOR ROTATING SAID ROTATABLEREOCRDING MEDIUM; COUPLING MEANS COUPLING SAID PRESENSING HEAD TO SAIDROTATING MEANS SO THAT SAID PRESENSING HEAD CONTROLS THE OPERATION OFSAID ROTATING MEANS TO INITIATE ROTATION OF SAID ROTATABLE RECORDINGMEDIUM; TRANSFER MEANS CONNECTED BTWEEN SAID SENSING HEAD AND SAIDRECORDING HEAD FOR TRANSFERRING SAID DATA SIGNALS FROM SAID ROTATINGRECORDING MEDIUM TO SAID ROTATABLE RECORDING MEDIUM, SAID TRANSFER MEANSCOMPRISING A FIRST GATE HAVING AN INPUT CONNECTED TO SAID SENSING HEAD,AN OUTPUT CONNECTED TO SAID RECORDING HEAD AND CONDUCTION CONTROL MEANS,SAID FIRST GATE BEING ADAPTED TO MAINTAIN UNDER THE CONTROL OF ITSCONDUCTION CONTROL MEANS ONE OF AN OPEN CONDITION IN WHICH IT CONDUCTSSAID DATA SIGNALS BETWEEN ITS INPUT AND OUTPUT AND A CLOSED CONDITION INWHICH IT BLOCKS SAID DATA SIGNALS; AND TRANSFER CONTROL MEANS CONNECTEDBETWEEN SAID PRESENSING HEAD AND THE CONDUCTION CONTROL MEANS OF SAIDFIRST GATE FOR CONTROLLING THE TRANSFER OF DATA SIGNALS THROUGH SAIDTRANSFER MEANS, SAID TRANSFER CONTROL MEANS COMPRISING A FIRSTMONOSTABLE MULTIVIBRATOR HAVING A FIRST OUTPUT CONNECTED TO THECONDUCTION CONTROL MEANS OF SAID FIRST GATE, A SECOND OUTPUT AND ANINPUT, A SECONMD GATE HAVING AN INPUT CONNECTED TO SAID PRESENSING HAD,AN OUTPUT CONNECTED TO THE INPUT OF SAID FIRST MONOSTABLE MULTIVIBRATORAND CONDUCTION CONTROL MEANS, SAID SECOND GATE BEING ADAPTED TO MAINTAINUNDER THE CONTROL OF ITS CONDUCTION CONTROL MEANS ONE OF AN OPENCONDITION IN WHICH IT CONDUCTS SAID DATA SIGNALS BETWEEN ITS INPUT ANDOUTPUT AND A CLOSED CONDITION IN WHICH IT BLOCKS SAID DATA SIGNALS, ANDMULTIVIBRATOR CIRCUIT MEANS CONNECTED BETWEEN SAID PRESENSING HEAD ANDTHE CONDUCTION CONTROL MEANS OF SAID SECOND GAGE FOR CONTROLLING INACCORDANCE WITH A PREDETERMINED TIME SEQUENCE THE CONDITION OF SAIDSECOND GATE AND THEREBY CONTROLLING THE CONDITION OF SAID FIRST GATETHROUGH SAID MONOSTABLE MULTIVIBRATOR, AND SAID COUPLING MEANS INCLUDINGSAID SECOND GATE AND A COUPLING CONNECTION BETWEEN THE OUTPUT OF SAIDSECOND GATE AND SAID ROTATING MEANS SO THAT SAID MULTIVIBRATOR CIRCUITMEANS ALSO CONTROLS THE OPERATION OF SAID ROTATING MEANS THROUGH SAIDSECOND GATE, SAID MULTIVIBRATOR CIRCUIT COMPRISING A BISTABLEMULTIVIBRATOR HAVING A FIRST INPUT CONNECTED TO THE SECOND OUTPUT OFSAID FIRST MONOSTABLE MULTIVIBRATOR, A SECOND INPUT AND AN OUTPUTCONNECTED TO THE CONDUCTION CONTROL MEANS OF SAID SECOND GATE, AND ASECOND MONOSTABLE MULTIVIBRATOR HAVING AN INPUT CONNECTED TO SAIDPRESENSING HEAD AND AN OUTPUT CONNECTED TO THE SECOND INPUT OF SAIDBISTABLE MULTIVIBRATOR.